Connecting part between leg prosthesis components

ABSTRACT

A connecting part of a ball joint between leg prosthesis components with a flange intended to fasten to the one component, the flange having an adjusting element position on it, consisting of a cup and a four-sided pyramid positioned centrally upon its point. To improve the adjustability of the connecting part, the flange is a rectangular flange with four holes, upon which the adjusting element is eccentrically positioned.

BACKGROUND OF THE INVENTION

The invention relates to the connecting part of a ball joint between legprosthesis components with a flange, intended to attach to one of thecomponents, on which there is an adjusting element, which consists of acup and four-sided pyramid set on its point on the center of the cup.

A corresponding embodiment can be derived from German Patent No. 19 22619. In this case, the adjusting element composed of the cup and thepyramid is placed exactly in the middle of the attachment flange. Byadjusting either of the two positional screws placed opposite eachother, the ball joint can be adjusted in only two defined levels. Thismakes it possible, for example, to position a leg prosthesisadvantageously on the load axis.

This previously known adaptor is generally used to connect theprosthetic substitute system to the prosthetic shaft for lower legstumps and short to medium-long upper leg stumps. In the case of poorstump positioning, for example in the flexing and/or splaying direction,which can be found in particular in the constantly growing group ofgeriatric patients with amputated legs, in some circumstances it may benecessary in designing the prosthesis to use most of the adjustment areawhich is available in each direction but which is limited by itsconstruction, so that the remaining adjustable area is no longersufficient for adjustment according to bio-mechanical criteria.

SUMMARY OF THE INVENTION

One purpose of the invention is to improve the adjustability of theinitially described connecting part.

This purpose is accomplished in accordance with the invention by makingthe flange a rectangular flange with four holes, to which the adjustingelement is eccentrically attached.

In accordance with the invention, as embodied and broadly describedherein, a connecting part of a ball joint for connecting first andsecond leg prosthesis components comprises a flange adapted to befastened to the first leg prosthesis component; and an adjusting elementpositioned on the flange, the adjusting element including a cup and afour-sided pyramid positioned centrally upon the cup on its point;wherein the flange is a rectangular flange having four holes; andwherein the adjusting element is eccentrically set upon the flange.

By rotating the rectangular four-holed flange in 90° segments around itscentral axis defined by the circular centering collar, it is nowpossible to make a center skew notch in the adjusting element in variousdirections for compensatory pre-positioning, without having to make useof the direction-specific adjusting field to any noticeable degree.

Various possible embodiments of the principle in accordance with theinvention, as well as the implementation will be explained in greaterdetail using the explanatory examples.

Additional objects and advantages of the invention will be set forth inthe description which follows and in part will be obvious from thedescription, or may be learned by practice of the invention. The objectsand advantages of the invention may be realized and obtained by means ofthe instrumentalities and combinations particularly pointed out in theappended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate a presently preferred embodimentof the invention, and, together with the general description given aboveand the detailed description of the preferred embodiment given bellow,serve to explain the principles of the invention.

The drawings show two embodiments of the invention which serve asexamples and a state-of-the-art embodiment. The following are shown:

FIG. 1--a connecting part in cross-section;

FIG. 2--the connecting part as in FIG. 1, from above;

FIG. 3--a modified embodiment illustrated as in FIG. 1;

FIG. 4--a top view of the embodiment illustrated in FIG. 3; and

FIG. 5--a ball joint connection between two leg prosthesis components,known from the prior art, shown schematically in side view and partly inlongitudinal view.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 5 shows an illustration from the previously published German PatentNo. 19 22 619. Attached to a leg prosthesis component 1 is a flange (notillustrated in greater detail) on which an adjusting element is placed,composed of cup 2 and a four-sided pyramid 3 positioned centrally on thecup on its point. A bushing 5 is attached to the upper end of a secondleg prosthesis component 4 in FIG. 5 and its upper free end isconstructed as ball socket 6, which rests on cup 2 and has fourboreholes in its surrounding shell, set at 90 degrees to each other andthreaded on the inside, each with set screw 7 threaded into it, theinner end of which lies against the attached wall of the four-sidedpyramid 3.

By loosening one set screw 7 and correspondingly tightening the opposingset screw, the adjustable ball joint can be swung in one defined planeand, upon corresponding adjustment of the two other set screws 7, in asecond swinging plane perpendicular to the first plane. Adjustment ofthe two set screws 7 illustrated in FIG. 5 thus brings about a swingingof the second leg prosthesis component 4, illustrated in the diagram,within the plane of projection in accordance with the dot and dashillustrations. In this way, for example, the adjustment of a legprosthesis can be set to the load axis. By loosening two adjacent setscrews 7, the two leg prosthesis components 1,4 can be separated, duringwhich process the two unloosened set screws 7 ensure that when the twocomponents are reconnected, the previously set angular position can befound again. The advantage of this construction is thus that the angleof the two leg prosthesis components 1,4 to one another is adjusted byswinging in only two defined planes each, and that each desired angleposition can be fixed and can be found again even after the twocomponents have been separated.

FIGS. 1 and 2 show an embodiment in accordance with the invention forone connecting part of the ball joint described above. The designprovides for a rectangular four-holed flange 8 on which the adjustingelement composed of the cup 2 and the pyramid 3 is eccentricallypositioned. This also applies to the modified embodiment in accordancewith the invention, as shown in FIGS. 3 and 4.

In the embodiment as in FIGS. 1 and 2, the central skew notch of theadjusting element 2,3 which is opposite the central axis 9 defined bythe circular centering collar of the flange 8, is made on a central lineparallel to two flange edges, whereas in the embodiment in accordancewith FIGS. 3 and 4 the central skew notch is made on one of the flangediagonals 10.

By rotating the rectangular four-holed flange 8, which is identical inthe two embodiments in accordance with the invention, in 90° segmentsaround its central axis 9, it is possible to set a central skew notch ofthe adjusting element 2,3 for compensatory pre-positioning;specifically, this is forward, outward, backward or inward in theembodiments in accordance with FIGS. 1 and 2 and forward/outward,outward/backward, backward/inward and inward/forward in the embodimentin accordance with FIGS. 3 and 4. In this regard, it is especially theflexibility of the backward and inward positions (embodiment inaccordance with FIGS. 1 and 2) or the backward/inward positions(embodiment in accordance with FIGS. 3 and 4) that is of particularimportance for the usual treatment.

Additional advantages and modifications will readily occur to thoseskilled in the art. Therefore, the invention in its broader aspects isnot limited to the specific details, and representative devices, shownand described herein. Accordingly, various modifications may be madewithout departing from the spirit or scope of the general inventiveconcept as defined by the appended claims and their equivalents.

What is claimed is: .[.1. A connecting part of a ball joint forconnecting first and second leg prosthesis components comprising: is,wherein the central axes are substantially parallel and offset..].2. Theconnecting part according to claim .[.1.]. .Iadd.5.Iaddend., wherein theadjusting element includes a central skew notch.
 3. The connecting partaccording to claim 2, wherein the central skew notch providescompensatory pre-positioning in forward, outward, backward, and inwarddirections.
 4. The connecting part according to claim 2, wherein thecentral skew notch provides compensatory pre-positioning inforward/outward, outward/backward, backward/inward, and inward/forwarddirections.
 5. .[.The.]. .Iadd.A .Iaddend.connecting part .[.accordingto claim 1,.]. .Iadd.of a ball joint for connecting first and second legprosthesis components comprising:a flange adapted to be fastened to thefirst leg prosthesis component; and an adjusting element positioned onthe flange, the adjusting element including a cup and a four-sidedpyramid having an apex, the pyramid being positioned centrally upon thecup on the apex defining a central axis; wherein the flange is arectangular flange having a central axis and four holes; wherein theadjusting element is eccentrically set upon the flange, that is, whereinthe central axes are substantially parallel and offset; and.Iaddend.wherein the adjusting element and the flange are one piece.
 6. Theconnecting part according to claim .[.1.]. .Iadd.5.Iaddend., whereineach of the four holes has a central longitudinal axis parallel to thecentral axis of the flange.
 7. .[.The.]. .Iadd.A .Iaddend.connectingpart .[.according to claim 6,.]. .Iadd.of a ball joint for connectingfirst and second leg prosthesis components comprising:a flange adaptedto be fastened to the first leg prosthesis component; and an adjustingelement positioned on the flange, the adjusting element including a cupand a four-sided pyramid having an apex, the pyramid being positionedcentrally upon the cup on the apex defining a central axis;.Iaddend.wherein the flange .Iadd.has a central axis and four holes, and.Iaddend.is rectangular in a plane orthogonal to the central axis of theflange.[...]..Iadd.;.Iaddend. .Iadd.wherein the adjusting element iseccentrically set upon the flange, that is, wherein the central axes aresubstantially parallel and offset; wherein each of the four holes has acentral longitudinal axis parallel to the central axis of the flange;and wherein the flange and the adjusting element aremonolithic..Iaddend..Iadd.8. A connecting part of a ball joint forconnecting first and second leg prosthesis components comprising: aflange having a central axis and four holes, the holes extending throughthe flange; and an adjusting element set upon the flange, the adjustingelement including a cup and a four-sided pyramid having an apex, theapex being positioned centrally upon the cup to define an adjustingelement central axis that is substantially parallel to and offset fromthe central axis of the flange; wherein the flange and the adjustingelement are contiguous; wherein the four holes are positioned in theflange at corners of a rectangular pattern that lies orthogonal to thecentral axis of the flange..Iaddend..Iadd.9. The connecting partaccording to claim 8, wherein the flange and at least a portion of theadjusting element comprise the same material..Iaddend..Iadd.10. Theconnecting part according to claim 8, wherein each of the four holes hasa central longitudinal axis parallel to the central axis of theflange..Iaddend.